Antihunting device for dynamo-electric machines.



I PATBNTED MAY 12, 1903. H. F. T. ERBEN. ANTIHUNTING DEVICE FOR DYNAMO ELEGTRIG MACHINES.

APPLICATION FILED NOV. 8, 1901.

10 MODEL.

5 wicnasses.

Inventor. Hermann FT. Erbe n.

UNITED STATES Patented May 12, 1903.

PATENT OF ICE.

IIERMANN F. T. ERBEN, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ANTIHUNTING DEVICE'FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 727,605, datedMay 12, 1903. Application filed November 8, 1901. Serial No. 811537. (No model.)

ToaZZ whom it may concern:

Be it known that I, HERMANN F. T. ERBEN, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Antihunting Devices for Dynamo-Electric Machines, of which the following is a specification.

My present invention relates to means for preventing hunting of dynamo-electric machines-such, for example, as synchronous motors, rotary converters, alternating-current generators, or the like-and comprises certain improvements, the novel features of which are particularly pointed out in the appended claims.

For a description of the in vention itself and of its mode of application in practice reference is to be had the following specification, taken in connection with the accompanying drawings, in which- Figure 1 represents an antihunting device made in accordance with my invention and shown as associated with the pole-pieces of a dynamo-electric machine. Fig. 2 is a detail view of the device itself separate from the machine to which it may be applied. Figs. 3 and 4. are views of component parts of the device; and Fig. 5 another view of the device, on an enlarged scale and partly in section.

The device consists of an arrangement of electric circuits adapted to be acted upon by flux passing through the pole-tips of the ma chine to which it is applied.

Specifically it consists of conductors looped or short-circuited about the pole-tips of a dynamo-electric machine, together with bridging-conductors extending between short-circuited conductors about adjacent pole-tips.

The particular mechanical structure is such that the device may be readily applied to the dynamo-electric machine or taken off without attendant difficulties.

Referring to Fig. 1, it will be seen that each pole-tip is slotted, as indicated, for example, at 1, 2, 3, and l. In each of these slots is placed a U-shaped piece of copper, brass, or other good conducting material, the two legs of the U being of slightly different lengths,

the purpose of which will shortly appear. This U-shaped piece is placed with its yoke in the slot," so that the legs of the U project outward from the pole-piece toward the next adjacent pole. A detail view of one of these U-shaped pieces is shown in Fig. 4, the longer leg being indicated at 5 and the shorter at 6. The position of the U-shaped piece with respect to the pole-tip is indicated both in Fig. 1 and in Fig. 5, in both of which views the longer leg of the U-piece is toward the observer. In Fig. 1 only a single pair of U shaped pieces 5 7 is shown; but it is to be understood that each pole-tip of the machine is to be similarly provided. In order to complete the circuits between the projecting legs of each pair of U-shaped conductors, I make use of a bridging member, which is, roughly speaking, of somewhat rectangular shape and of open construction. This bridging-piece or bridge is shown indetail in Fig. 3 and consists of the two side bars 8 9, connected by the outwardly-bowed end pieces 1O 11. The outer edges 10 11 of the side pieces 8 9, respectively, are adapted to slide into grooves formed on the outer edge of two adjacent pole-tips. In Fig. 1 two of these grooves are indicated at12 and 13, while in Fig. 5 the conducting-bridge is shown in engagement with such a groove at 14.. Each end of the bridge is provided with a pair of projecting lugs, which serve as a means of engagement between the bridge and the U- shaped conductors already described. Both Figs. 2 and 3 clearly illustrate these projecting lugs. By inspection of these figures one end of the bridge will be seen to be provided with a pair of lugs 15 16,projecting substantially at right angles to the bars 8 9, while at the other end of the bridge will be seen two other projecting lugs 17 18, projecting from the bridge in the same direction as the corresponding pair of lugs 15 16. The lugs of one pair are, however, offset from those of the other pair, as indicated, perhaps, best in Fig. 5, which shows an end View of the bridge with one of the U-shaped pieces cut away, as at 19. In this figure the lug nearest the observer will be seen at 18, while the lug corresponding to 16 in Fig. 3 will be similarly seen 10- cated backward of the lug 18, but oifset to one side thereof. With this construction it will be noted that if the U-shaped pieces 5 7 are inserted in position, as shown in Fig. 1, with the longer legs of the pieces toward the observer the bridge may be slid in between the pole-pieces from the opposite side of the machine. In such a case the edges 10 11 of the bridge will slide in the opposing grooves made in the adjacent pole-pieces, and owing to the offsetting of the lugs 17 18 toward thecenterline of the bridge these lugs will slide by the ends of the shorter legs of the Upieces, and the bridge may be moved into the position represented in Fig. 2, where the lugs 17 18 are brought up against the longer legs of the U-pieces and the lugs 16 against the shorter legs. In this position the bolt 20, extending between the connecting-bars of the bridge, may be drawn up tightly, thereby bringing toward each other the convex ends of the bridge and so forcing the sides of the bridge firmly into contact with the cooperating pole-corners. Bolts or screws 21 to 24 may be used to secure firm contact or electrical connection between the lugs of the bridge and the legs of the U-shaped pieces. In taking the bridge apart it is of course only necessary to go through the reverse of the operations already described.

In case of hunting of the machine to which the device above described is applied the flux through the pole-corners varies periodically, and this variation is strongly opposed by currents set up in the system of conductors connected thereto. This reaction operates as a powerful restraint upon any tendency to hunt which the machine may have.

No further description of the operation of the device appears necessary, since devices of the same general character are already well known in the art and their mode of operation well understood.

NVhat I claim as new, and desire to scour by Letters Patent of the United States, is-

1. The combination with a dynamo-electric machine, of a bridge of conducting material located between adjacent poles of said machine, and conductors embracing each of said poles and separably and electrically connected to said bridge.

2. An antihunting device for dynamo-electric machines consisting of a bridge member, and U-shaped conductors connected to said member. t 3. The combination of a dynamo-electric machine having pole pieces provided with grooves, U shaped members of good conducting material in said grooves, and a bridging member adapted to engage U-shaped members of two adjacent pole-pieces.

4. The combination with a dynamo-electric machine, of short-circuited conductors looped about the pole-tips of said machine, and bridging-conductors extending between adjacent pole-tips and connected to the short-circuited conductors looped about the last-mentioned tips.

5. An antihunting device consisting of a bridging member, lugs on each end of said member, the lugs on one end being offset from the lugs on the other, and U-shaped members secured to said lugs.

6. The combination with a dynamo-electric machine provided with pole-pieces, ofa bridging member with parallel sides adapted to slide between and engage opposing pole-tips of two'adjacent pole-pieces, a slot in the face of each of said adjacent pole-pieces, and a conductor in each slot having ends bent around or ext-ending so as to engage said bridging member.

7. The combination with a dynamo-electric machine provided with pole-pieces, ofa bridging member with parallel sides adapted to slide between and engage opposing pole-tips of two adjacent polepieces, lugs on said bridging member located at the extremities of said parallel sides, a slot in the face of each of said adjacent pole-pieces, and a conductor in each slot having ends bent around or extending so as to engage lugs on said bridging member.

In witness whereof I have hereunto set my hand this 6th day of November, 1901.

' HERMANN F. T. ERBEN.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

